Direct ignition for fuel burners



March 2, 1965 H. A. MUDD DIRECT IGNITION FOR FUEL BURNERS 3 Sheets-Sheet 1 Filed Sept. 15, 1960 MIX/UM TLUPf/PATURE Macaw-a2: #4227 41 All/l] March 2, 1965 H. A. MUDD DIRECT IGNITION FOR FUEL BURNERS 3 Sheets-Sheet 2 Filed Sept. 15, 1960 /#r.ewroz: #4 KW? A7. M017] JXJWM ,4 577441 March 2, 1965 H. A. MUDD DIRECT IGNITION FOR FUEL BURNERS Filed Sept. 15, 1960 3 Sheets-Sheet 5 k I I I 0 R L 4 a i w 3337 3 |lI|L w K I Q, M

6 f a 3 5 In... w fi w L United States Patent 3,171,469 DIRECT IGNITION FOR FUEL BURNERS Harry A. Mudd, Clayton, Mo., assignor to McQuay-Norris Manufacturing Company, St. Louis, Mo., a corporation of Delaware Filed Sept. 15, 1960, Ser. No. 56,284 Claims. (Cl. 158-125) This invention relates to direct ignition for fuel burners and more specifically to an electric control system including an electric ignitor of the make and break type which is adapted for connection to, and direct ignition of, a main gas burner for various kinds of gas fired appliances. This invention eliminates the need for a socalled pilot light or pilot burner and the safety systems associated therewith. The direct ignition, hereinafter illustrated, is described as it is adapted to the use in clothes driers for home use, but as this description proceeds it will become apparent to those skilled in the art that this direct ignition is applicable to gas fired heaters, gas fired incinerators and other gas appliances using gas fired burners which must be operated intermittently rather than continuously. In other words, direct ignition is a substitute for a gas pilot light or the like.

Most clothes driers for domestic use operate on the same principle. The clothes to be dried are placed in a closed. chamber in which they are agitated, and are subject to a circulation of air to absorb the water from the clothes. Usually a fresh continuous supply of air is heated by a gas burner and then circulated by force through the chamber in which the clothes are being agitated. Ordinarily, drying machines are equipped with controls for limiting the duration of the cycle and the maximum temperature attained in the drying chamber. The timing switch or timer determines the duration of the drying period while the maximum temperature limit switch turns off the gas burner when the temperature in the drying chamber reaches a preset maximum during the circulation of air in the chamber. When the chamber temperature has fallen to a predetermined lower value, the maximum temperature limit switch conditions the control system to relight the gas burner. Consequently, during a drying cycle determined by the timer switch, the gas burner is turned olf and on repeatedly. Obviously, such a system would be incomplete without some means for relighting the gas burner. Heretofore, a gas pilot light or burner was provided for this purpose, and the control system for the burner included also a control system for the pilot burner so interlocked in the control system that unless the pilot burner was operating the main burner control valves remain closed. Thus, such systems were complicated by providing an ignitor for the pilot burner connected with a solenoid for the pilot burner valve which were operated simultaneously, together with a flame switch heated by the pilot burner which could disable the ignitor and condition the control system for the operation of the main burner control valve. Prior systems for direct ignition of the main burner are also known in which the ignitor is a sparking plug operating at about 4000 volts input.

It is one of the objects of this invention to eliminate from burner control systems some of the complication necessary when a pilot burner is used.

It is another object of this invention to eliminate the presence of higher voltage in such control systems in which direct ignition is obtained by a sparking plug.

It is a further object of the invention to improve the dependability of systems for direct ignition of main fuel burners.

It is still a further object of the invention to obtain a system for direct ignition of main fuel burners which will fail safe.

According to this invention, the fuel supply for a main fuel burner is controlled by a circuit which includes a starting circuit for the ignition cycle connected to an ignitor circuit energizing make and break electric contacts generating the ignition spark to ignite the main fuel burner after operation of the main fuel burner valve. Ignition of the main burner in turn disables the ignitor circuit. The invention also includes a timer switch for the starting circuit in case the main burner does not light, which timer switch temporarily de-energizes the control circuit. The power actuation of the make and break contacts may be electrical or pneumatic, both kinds will be hereinafter described. The contacts themselves have been found to be extremely durable when constructed of a suitable alloy such as one of tungsten and thorium. When the current is limited to between /2 and 1 ampere at volts, contact life is measured in millions of cycles.

The following is a detailed description of the invention in such full, clear, and exact terms as to enable any person skilled in the art to make and use the same when taken with the illustrations in the accompanying drawings in which:

FIG. 1 is an environmental view illustrating schematically the general arrangement of machine elements of a drier machine;

FIG. 2 is a wiring diagram of the control circuit for the drier illustrated in FIG. 1;

FIG. 3 is a perspective view schematically illustrating a switch mechanism for direct ignition of a fuel burner;

FIG. 4 is a view similar to FIG. 3 illustrating the reverse side of the mechanism;

FIG. 5 is a perspective view schematically illustrating an electrically heated thermostatic switch, termed a warp switch, for controlling the cycling of the ignition;

FIG. 6 is a wiring diagram of a modified form of the invention; and

FIG. 7 is a perspective view of an ignitor employed in the embodiment illustrated in FIG. 6.

FIG. 1 shows a schematic arrangement of the elements of a drying machine so arranged as to facilitate an understanding of this invention. The arrangement shown herein is not the usual commercial construction and is intended to be illustrative only. According to FIG. 1, a drying chamber C in the form of a cylindrical housing is mounted on a pedestal P and provided with a round door D for access to the chamber C. Within the chamber C is an agitator for moving the clothes around in the chamber C during the drying operation to permit exposure of the surfaces of the clothes to the drying current of air. Air is supplied from the inlet A to the chamber C by a blower F, and the air from the blower F passes over a burner B on its way to the chamber C. The addition of heat from the burner B to the current of air from the blower F raises the temperature of the air and thereby decreases its relative humidity. This warm current of air picks up moisture from the clothes within the chamber C and then discharges from the chamber C by Way of the stack S, preferably to outside atmosphere. The agitator within the chamber C and the blower F are driven from an electric motor M which has a suitable drive pulley engaging the belt VB which in turn is trained over driven pulleys on the shaft of the blower F and on the agitator shaft (not shown). The burner B is supplied with fuel from a gas main GM which connects with a solenoid operated dual valve and regulator DVR located in a suitable housing. The dual valve and regulator DVR can be of conventional construction well known in the art, and is so located in the gas main GM as to control the flow of gas to the burner B. It is therefore one of the control elements. Adjacent the burner B is another control element, the ignitor 16, which will be described more in detail hereinafter. Adjacent the door D is a door switch D8 which is opened when the door is opened and closed when the door D is closed. This switch is installed in the system as a safety device. the chamber C is a control box CB. Within the box CB are the control elements, mechanisms and control circuits which are connected with the ignitor IG, the dual valve and regulator DVR, motor M and door switchDS by interconnecting conduits W, X, Y and Z which enclose the wiring harness forming the necessary circuits for operation of each of these control elements from the control circuit within the box CB; These circuits are in turn con-. nected with house current of 11 5 volts by the portable cord PC and the electric plug ER. Also connected with the control box CB is a temperature sensing means SM which extends from the control box to within the chamber C. The above description willsuffice as background Shown on the top of,

through the conduits W, X, Y and. Z to the various control elements to which they are connected, respectively.

, The burner circuit also includes a holding circuit which has a resistor 35 connected with the lead 18 and by alead 36' extending to the opposite end of the solenoid coil 20, heretofore mentioned. The holding circuit maintains the relays .15 closed after the burner circuit has been once energized by operation of the starting circuit.

The starting circuithas a lead 40 extending from switch FSby connection with lead 14. .The starting circuit re- I mains open until all of the switches TS, DS and FS are for an understanding of the invention which pertains to j direct ignition of the fuel burner B by the ig'nitor IG and to the control system within" the control box CB which is connected thereto and withthe other elements "of a control, such as door switch DS, dual valve and regulator DVR and motor M. V f

Attention is now directed to FIG. 2, which, illustrates schematically the wiring diagram and control mechanism within the control box CB and its electrical interconnection with the other control elements, With reference to this same figure, the control box CB contains two switches TS and PS. The switchTS is a settable clock switch with an externally exposed knob carrying an indicator and operating over an indicator dial. 'By movement of the exposed knob on the switch'TS,"the total time or duration of the drying cycle is'set. Switch FS is operated by 7 box CB, which will be described consecutively.

Line L1 connects to a lead 10 to the switch, heretofore mentioned, TS and to a line 11 which extends to one terminal ofthe door switch DS. The otherterminal of the door switch DS is connected by 'a lead 12 with lead 31 tomotor M and 32 from the motor M to the line L2, so that when switches TS and D8 are closed motor M operates to drive the blower F and agitator. connects with switch FS'in the burner circuit and by a lead 14 with a fixed terminal 13 of a relay 15. Relay 15 is normally open and closed by energization of its solenoid 20. Movable contact. 16 is connected by a lead 18 with the solenoid operating mechanism of the dual valve and regulator DVR, shown schematically within its own casing. closed and opened for regulation of the gas flow only when energized. A lead 23 extends from the opposite end of the solenoid of the valve DVR to timer switch 25 which has a movable contact 26 normally closed with a relatively stationary contact 28 of the warp switch 25. Lead 30 connects the fixed contact 28 with input line L2 to complete the burner circuit. Lines 31 and 32 are connected respectively to leads 12 and 36' and' extend to the motor M. It will be noted that lead 31 is in series relation with the switches TS and DS, so that motor M is operating when these switches are. closed. The pairs of leads 11, 12 and 31, 32 and 18, 23 have been shown as extending from the casing of housing ,CB'

This .valve regulator is normally closed. Lead 40, extends to fixed terminal 41 of the flame switch, generally indicated as 42. The movable contact 43 of'this switch is connected by a lead 45 with a resistance heater 46 on the warp switch 25, and resistance heater '46 is connected by a lead. 47 in series With aresistor 48to the solenoid 20 andlwith lead .30 to input line L2.

' The ignitor circuit has a lead 50connected with the starting circuit between the flame switch 42 and the timer switch25 which connects to the ignitor within the housingIG. Lead 50 has .two branches, one of which 51 connects with one terminal of a motor 52 and the other of which 53 connects with one of the make-and break contacts 55 through an inductance 56 which limits the current flow to the contact 55' to 4A2 to l ampere. Contact .57 of the make and break ignitor is connected by a lead 58 to a lead 59 which extends from the motor 52 to the line 30 through the timer switch 25. 'As will hereinafter be described, the motor 52' operates the; make and break contacts55 and 57 into'and out of contactso as; to create 7' a spark for direct ignition of the burner B.

FIGS. 3 and 4 show two views of a combined flame switch and ignitor switch suitable for the above'system.

A metal. stamping forms a support for this switch and carries at its upper end an offset ear portion 69. extending laterally from the support 65 in one direction and a lateral extending part 68 in the opposite direction. Be-

low the extension 69ris a U-shaped bracket having a portion71 overlying the support 65. 'Riveted to the'overlying portion 71 is one leg 72 carrying oneof the contacts 57 of the make and break. 'Support 65 also has an ottset b'racket'73 having a portion 74 spaced from the support portion 65 and in an offset plane with relation there- Line 12 also to. Bracket 73 has an insulated fiber support 77 riveted thereto which carries on its lower side a leg 75 mounted thereon to oscillate so that contact 55 carried thereby may bemoved into and out of engagement with the contact 57 on thel eg 72; Leg 75 has a cam follower 76 positioned'to be engaged by the ratchet shaped teeth 79 on the. fiber cam 80. Motor 52 drives shaft 81 carrying cam preferably at a speed of about the distance between ratchet teeth-79 in one second. The leaf spring at different points. Actually this is merely an expedient to clarify the illustration, as it will be understood, that all of these leads extend from the control housing C8 'the contacts back together.

85 is riveted to the upper side'of insulating member 77 and has a projection 86 tending 'to force the contacts 55 and 57 together. "The construction is such that when motor 52.is operating, the contacts 55 and 57 are separated rapidly by the action of the ratchet teeth 79'engaging the follower 76,. Between teeth,spring 85 forces Turning now to FIG. 4, the extension 68 is apertured at 88 to receive a switch operating arm 89. Between the upper end of operating arm 89 and extension 69'is a flame deflector 90with a pair of laterally extending legs 91 and 92 wedged between the inner surface of the ex tension 69 and inner surface of the switch operating arm 89. Legs 91 and are supported in this position by pin extensions projecting through suitable apertures 'in the. extension 69 and the switch operating arm 89.

Flame deflector 90 has a tongue 94 received in a groove in the bracket 65 was to'maintain the "deflector 90 in position against rotation. It will be understood that the tongue 94 has a loose fit in a slot in the bracket 65 so as to permit slight movement of theflame deflector 90. One leg of angular piece 96 is secured to the bracket 65 by suitable rivets, and the other leg is threaded to receive a stud 98 which projects through a suitable aperture 99 in the switch operating arm 8% and bears against a leaf spring 100 secured at 101 by suitable rivets to the switch operating arm 89. The pressure of the stud 93 against the leaf spring 100 maintains the upper end of the switch operating arm 89 firmly pressed against the end of the leg 92 of flame deflector 90. As a safety measure, an additional spring, such as coil spring 103, may also be interposed between the switch operating arm 89 and angular piece 96. Both springs 100 and 103 tend to urge the switch operating arm 89 in a direction to press the adjustable set screw 1% into engagement with the operating button of microswitch 42 so as to maintain the switch 42 closed. A guard, such as 110, projects in spaced relation to the flame switch mechanism so as to protect it.

The flame deflector 90 is positioned next to the burner B in such a way as to be in direct path of the flame from the burner B and to position the make and break contacts 55 and 57 in a readily combustible area of the mixture issuing from the burner B. The direct ignition of the fuel from the burner B is accomplished by the operation of the ignitor switch and its make and break contacts, but after the burner B has been ignited, the flame will impinge upon the flame deflector 90 heating the flame deflector and causing its extensions 91 and 92 to expand rapidly. The expansion will exert a pressure against the switch operating arm 89 above its fulcrum point 33 so as to compress spring 103 and deflect spring 100. A short period of heating of the flame deflector 9t? is sufflcient to produce a substantial movement of the lower end of the switch operating arm 89 moving the adjusting screw 1% away from the switch 42 to allow the switch to open. Unless the flame deflector is heated, the switch 42 remains closed.

The warp switch in the above described circuit is shown schematically in FIG. 5. Two bi-metallic blades 12d and 121 are mounted in spaced relation in an insulating support 123. The inactive ends of the blades 120 and 121 are provided with electrical connections 124 and 125, respectively. The active ends of the blades 120 and 121 carry a relatively movable contact 26 and a relative fixed contact 28, which are normally held together regardless of ambient temperature, since both blades 129 and 121 are subject to the same temperature, ordinarily they will follow one another in direction of movement in response to changes in ambient. On the blade 12d and located between the two blades is a resistance heater 46. A pigtail 130 connects one end of the resistance heater 46 to the connector 125. The opposite end has a short connection 131 with the blade 129 itself. When the resistance heater 46 is active, it will rapidly affect the tempcrature change in the blade 120 by conduction and radiation from the heater. The effect of heater 46 on the blade 121 is not a direct one, although some heating of the blade 121 will take place when the heater 46 is active. Thus, when the heater 46 is active, both blades 120 and 121 will respond by deflecting together in the same direction, but the blade 120 will move faster so as to open the contacts 26 and 28 after a relatively short time. When the circuit to the heater 46 is then opened, there is a cooling period during which the contacts 26 and 28 remain open, but this cooling period is relatively short before the contacts 26 and 28 close. This switch, therefore, provides a cycle in which, during operation of the heater 46, contacts 26 and 28 remain closed for approximately 45 seconds and then open. Ignition normally occurs and flame switch 42 opens in less time than this so that unless ignition fails the warp switch never opens. When the heater is de-activated, the contacts remain open for about seconds and then close since the blade 121 lags in its response to the heater 46, both in opening of the contacts and in closing of the contacts.

Operational sequence of direct ignition FIG. 2 represents the position of the control elements at the start of the cycle. Clock switch TS has been closed setting a time for drying, the chamber C has been charged with the wet clothes and the door closed, closing the door switch DS, and, of course, since the temperature sensed in the chamber C is far below the maximum set by the switch FS, that switch also will be closed so that the circuit is completed through switches TS and DS to the drive motor starting the blower F and the agitator within the chamber C. The closing of the above named switches initiates a cycle to open valve DVR and to produce direct ignition by ignitor IG. Attention is now directed to the circuits for performing these functions. Of course, when the burner B is not in operation, flame switch 42 is closed, and this in turn energizes the starting circuit. This circuit as aforedescribed includes leads 40 and 45 to the heater 46 of the warp switch 25 to resistor 48 and the solenoid coil 20 of the relay 15 to the line L2. Solenoid 2t) closes relay 15 and this in turn energizes the burner circuit through the leads 18 to the dual valve and regulator DVR and from the regulator through the warp switch 25 to the line L2. Energization of the dual valve and regulator opens communication between the burner B and the gas main GM. A burnable mixture then discharges from the burner B adjacent the make and reak contacts 55 and 57. At the same time, the ignitor circuit is energized through the lead 50 to the motor 52, and make and break contacts 55 and 57 which begin to operate generating a spark on each break. Usually the burner is directly lighted within a few seconds, and the flame then impinges against the flame deflector of the ignitor switch 42 heating the flame deflector and causing the switch operating arm 89 to be biased against the pressure of the springs 109 and 103 to open flame switch 42. This usually occurs in 15 seconds or less. After switch 42 opens, relay 15 is maintained closed by the holding circuit through the resistor 35 to this relay coil 20, but both the starting circuit and the ignitor circuit are broken by opening of the flame switch 42, thus, deenergizing both circuits. This stops the operation of the motor 52 and of the make and break contacts 55, 57. It also opens the starting circuit which includes the heater 46 of the timer switch 25 so that the switch 25 remains closed.

If the switches TS, DS and FS are closed and for some reason the burner fails to light the warp switch 25 comes into action and after a period of 45 seconds it reaches a temperature due to the energization of the heater 46 to separate the contacts 26 and 28. When contacts 26 and 28 separate, the burner circuit is de-energized allowing the valve DVR to close and shut off the supply of fuel to burner B. The ignitor circuit is also opened by the operation of the warp switch stopping the action of the make and break contacts. The starting circuit remains closed however, holding the relay 15 closed and the warp switch open indicating a failure in the system. This failure may be indicated by a signal light, if desired. Such a system will fail safe under all foreseeable circumstances, for the reason that the starting circuit controls the relay 15 in the burner circuit. Any failure which open the starting circuit would initially fail to energize coil 20 so that the burner circuit would remain open and the burner shut off. If either the heater 46 or resistor 48, or both, were not series connected in the starting circuit with the coil 2% either one or both, as the case might be, could fail without opening the starting circuit, and this failure would never be detected by a normal starting cycle. But, in the event of ignition failure when the flame switch 42 remained closed, the burner valve would remain open. With the present system, the burner valve remains closed if there is an open circuit in either the starting circuit or burner circuit, or the burner valve will be closed by opening of the warp switch 25 in the event of ignition circuit misfunctioning.

7 If the door D is opened before a drying cycle is complete the door switch DS opens to deenergize the holding circuit for the relay 15. The blade 16 moves away from the contact 13 and the circuit to the valve DVR is opened so that the supply of fuel to the burner B is interrupted. The flame switch 42 is then in the open position and the starting circuit and the ignitor circuit are both deenergized whereby opening and reclosing of the door switch DS leaves the system temporarily inoperative. No start can be made untilthe flame switch 42 again closes. This system is therefore so interconnected between the several circuits as to'fail safe under any condition.

FIG. 7 shows a modified form of an ignitor. which combines the function of the reluctance 56, the make andbreak contacts 55, 57 and the motor 52. This modified form may=replace the mechanism heretofore illustrated and described with respect toFIG. 3 in the control circuit:

illustrated in FIG. 2, etc. Since the ignitor device illus= trated in FIG. 7'is in most respects constructed'as shown in FIGS. 3 and 4 and heretofore described, the following description will be limited to distinguish the modified form from the prior showing, it being understood that in the respects not herein specifically mentioned, the modi fied form does not differ from that shown in FIGS. 3 and arm 72 which is in turn electrically connected through the lead 50. Contact 57' on the flexible steel arm 75 is movable with respect to the contact 55' by flexing of the arm 75' which is rigidly mounted on a bracket 74' offset from the body portion of the ignitor. The flexible arm 75 has a parallel portion spaced therefrom indicated as 77'. Secured to the portion 77' and extending close to the surface of the arm 75" are a pair of coils 56. The coils 56 are wound' on suitable soft iron cores 256 and 257 and are electrically connected at 258 with the movable arm 75'. The. two coils are connected 'in'series with the lead 58 bya short connection 259 at their adjacent ends. 7 r

When the contacts 55' and 57' are together, the circuit is completed from the lead 50 to the lead 58through the contacts and through the coils 56 which act as an inductance to limit the current flow across the contacts 55' and 57'. Likewise, when the contacts 55' and 57' are closed, the coils 56' are energized to form a magnetic field which draws the arm '75 toward the coils separating the contacts 55' and 57. Separation of the contacts breaks the circuit tie-energizing the coils 56' and the resil ience in the arm 75' again closes the contacts to repeat the cycle. The spark generated by the make and break contacts 55 and 57' will perform the function of ignition the same as contacts 55 and 57 in the embodiment shown in FIG. 3.

FIG. 6 illustrates the circuit shown in FIG 2 modified to connect thereto the ignitor shown in FIG. 7. -As will be readily recognized, the substitution of the ignitor 8 nected'to said electricallyoperated valve and through switch means to a source of electric power, a timer switch connected in said burner circuit with said source of electric power for energizing said electrically operated valve to' open and for, de energizing said electrically operated valve to close, a timer element in said timer switch, a starting circuit connected with said source of electric power and with said burner'circuit for initially energizing said burner circuit to open said electrically operated valve when said switch means are closed, an ignitor circuit connected with said source of electric power by said timer switch to be energized and de-energized by closing and opening of .said timer switch when said switch means are closed, a pair of make and break ignition points in said ignitor circuit connected in series with said timer switch, a flame switch responsive to'heat from said fuel burner for connecting and disconnecting said source of electric power and said starting circuit, means in said starting circuit controlled by said flame switch when closed to initiate the timer element in said timer switch and to de-energize the timer element when said flame 7 switch opens at high temperatures, and means to move said make and break ignition points into and out of contact in response to opening of said electrically operated valve as long as said flame switch remains closed and said burner circuit is energized. a

2. An electrically energized direct ignition system for a fuel burner having a source of fuel controlled by an electrically operated valve comprising, a burner circuit connected to said electrically operated valve and through switch means to a source of electric power, a timer switch connected in said burner circuit with said source of electric power for energizing said electrically operated valve to open and for de-energizing said electrically'opershown in FIG. 7 affects only the so-called ignitor circuit. 7

This description of the circuit will be limited to the changes in the ignitor circuit. g

Lead 50, which connects with lead 45 to the heater element 46, is in turn connected with the fixed arm 72 and contact 55'. Contact 57' on the fiexible arm 75 is held in contact with 55'- by spring or by the inherent resilience in the steel arm 75' and this in turn connects. the coils 56' into the circuit in series with the contacts 55', 57' and the lead 53' which extends to the timer switch 25.

The operation of the circuitin FIG. 6 is thesame as that in FIG. 2.

Changes in and modification of the construction here 1. An electrically energized direct ignition system for a fuel burner'having a source of fuel controlled by an electrically operated valve comprising, a burner circuit con-.

ated valve to close, a timer element in said timer switch,

a starting circuit connected with said source of electric power andwith said burner circuit for initially energiz-. ing said burner circuit to open said electrically operated valve when said switch 'means are closed, an ignitor circuit connected with said source of electric power and said timer switch to be energized and de-energized by closing and opening of said timer switch when said switch means are closed, a pair of makeand break ignition points connected in said ignitor circuit in series with said timer switch, aflame switch responsive to heat from a fuel burner for connecting and, disconnecting saidsource of electricpower and saidstarting circuit, means in one of said circuits controlled by said flame switch when closed to initiate the timer element in said timer switch and to de-energize the timer element when said flame switch opens at high temperature, an electric motor connected to said ignitor circuit and energized therefrom and cam means for opening said make and break points slowly and closing said points relatively rapidly actuated by said electric motor. I

3. An. electrically energized direct ignition system for a fuel burner. having a source of fuel controlled by an electrically'operated valve comprising, a burner circuit connected to said electrically operated valve and through switch means to a source of electric power, a timer switch connected in said burner circuit with said source of electric power for energizing said electrically operatedvalve to open and for tie-energizing said electrically operated valve to close when said switch means are closed, a timer element in said timer switch, a starting circuit connected with i'said source of electric power and with said burner circuit for initially energizing said burner circuit to open said electrically operated valve. when said switch means are closed, an ignitor circuit connected with said source of electric power and said timerswitch to be energized and de-energized by closing and opening of said timer switch when said switch'means are closed, a pair of make and break ignition points in said ignitor circuit connected in series with said timerswitch, a flame switch respon- ,sive to heat "from a fuel'burner for connecting and disconnecting said source of electric power and said starting circuit and said ignitor circuit, means in the circuit controlled by said flame switch when closed to initiate the timer element in said timer switch and to de-energize the timer element when said flame switch opens at high temperature, cam means for opening said make and break ignition points slowly and closing said points relatively rapidly, a motor connected to operate said cam means and means to energize said motor in response to opening of said electrically operated valve.

4. An electrically energized direct ignition system for a fuel burner having a source of fuel controlled by an electrically operated valve comprising, a burner circuit connected to said electrically operated valve and a source of electric power, a timer switch connected in said burner circuit with said source of electric power for energizing said electrically operated valve to open and for de-energizing said electrically operated valve to close, a timer element in said timer switch, a starting circuit connected with said source of electric power and with said burner circuit for initially energizing said burner circuit to open said electrically operated valve, an ignitor circuit connected with said source of electric power and said timer switch to be energized and de-energized by closing or opening of said timer switch, a pair of make and break ignition points in said ignitor circuit connected in series with said timer switch, a flame switch responsive to heat from a fuel burner connected between said source of electric power and starting circuit and ignitor circuit, means in one of said circuits controlled by said flame switch when closed to initiate the timer element in said timer switch and to de-energize the timer element when said flame switch opens at high temperature, a holding circuit connected in shunt relation with said timer switch to said burner circuit, and means to move said make and .break ignition points into and out of contact in response to opening of said electrically operated valve.

5. An electrically energized direct ignition system for a fuel burner having a source of fuel controlled by an electrically operated valve comprising, a burner circuit connected to said electrically operated valve and a source of electric power, a timer switch connecting in said burner circuit with said source of electric power for energizing said electrically operated valve to open and for de-energizing said electrically operated valve to close, a timer element in said timer switch, a solenoid operated relay in said burner circuit connected in series between said source of electric power and said electrically operated valve, a starting circuit connected with said source of electric power and with said burner circuit by way of the solenoid of said relay switch for initially closing said relay switch to energize said burner circuit to open said electrically operating valve, an ignitor circuit connected with said source of electric power and said timer switch to be energized and de-energized by closing or opening of said timer switch, a pair of make and break ignition points in said ignitor circuit connected in series with said timer switch, a flame switch responsive to heat from the fuel burner and connected between said source of electric power and said ignitor circuit, and adapted when cold to supply power to operate said make and break ignition points, a holding circuit energized by closing of said relay switch and connected with said burner circuit to energize the solenoid of said relay switch when said flame switch opens at high temperature, and means to move said make and break ignition points into and out of contact in response to energization of said ignitor circuit.

6. An electrically energized direct ignition system for a fuel burner having a source of fuel controlled by an electrically operated valve comprising, a burner circuit connected to said electrically operated valve and to a source of electric power, a timer switch in said connection, a timer element in said timer switch, a starting circuit connected with said source of electric power and with said burner circuit for initially energizing said burner circuit to open said electrically operated valve on closing of said timer switch, an ignitor circuit connected with said source of electric power and with the timer element in said timer switch for operating said timer switch to close to energize said burner circuit during starting and subsequently open said burner circuit if ignition fails, a pair of make and break ignition points in said ignitor circuit connected in series with said timer switch, a flame switch responsive to heat from the fuel burner connected between said source of electric power and said ignitor circuit for initially closing said timer switch and energizing said make and break ignition points, a motor in said ignitor circuit, and cam means connected with said motor and said make and break ignition points for opening said points slowly and closing said points relatively rapidly.

7. An electrically energized direct ignition system for a fuel burner having a source of fuel controlled by an electrically operated valve comprising, a burner circuit connected to said electrically operated valve and to a source of electric power, a switch connected in said burner circuit with said source of electric power for energizing said electrically operated valve to open and for de-energizing said electrically operated valve to close, an ignitor circuit connected with said source of electric power and connected with said burner circuit to be energized and de-energized by closing or opening of said switch, a flame switch connected with said ignitor circuit in series with said first switch for de-energizing said ignitor circuit when open and for energizing said ignitor circuit when closed, said flame switch having a flame deflector exposed to the head from the burner, a fixed and movable abutment between which said flame deflector is mounted and a micro-switch operated by said movable abutment, a pair of make and break ignition points connected in said ignitor circuit in series with said flame switch and mounted adjacent thereto, motor means energized by operation of said electrically operated valve, cam means driven by said motor means for opening and closing said make and break ignition points, an inductance means connected in said ignitor circuit for limiting the current between said make and break ignition points.

8. The combination as defined in claim 7 wherein said make and break ignition points are an alloy of metal including tungsten and thorium.

9. A system for controlling the operation of a fuel burner having a source of fuel and an electrically controlled regulating valve between the source and the burner, comprising an electrically powered circuit connected to drive an electric motor furnishing power for supplying air to said burner, a starting switch in said electrically powered circuit, a burner control circuit connected to said electrically controlled regulating valve and said motor circuit, a maximum temperature limit switch responsive to heat from the burner for controlling the connection between said burner control circuit and said electrically powered circuit, switch means for opening and closing said burner control circuit, an electrically powered starting circuit for actuating said switch means, an ignitor circuit connected to said starting circuit and with said switch means in said burner circuit so as to be energized when said burner circuit is closed by said switch means, a make and break ignition device connected to said ignitor circuit with said ignition device located adjacent the fuel outlets of said burner and a flame switch responsive to heat from said main burner to open and prevent energization of said burner control circuit on reclosing of said temperature limit switch.

10. A system for controlling the operation of a fuel burner having a source of fuel and an electrically controlled regulating valve between the source and the burner, comprising an electric powered circuit connected to drive an electric motor furnishing power for supplying air to said burner, a starting switch in said electric powered circuit, a burner control circuit connected to said electrically controlled regulating valve and said motor ing circuit connected to operate said relay to close and to initiate operation of said timer switch, an ignitor'circuit connected to said starting circuit and with said switch means in said burner circuit so as to be energized when said relay is closed and de-energizedwhen' said timer switch opens, a make and break ignition device conn'ected to said ignitor circuit with said ignition device located adjacent the fuel outlets of said burner, and a flame switch connected to control said starting circuit and responsive to ignition of said burner 'to terminate operation of said timer switch. on ignition of saidburner.

References Cited by the Examiner UNITED STATES I PATENTS 7 933,450 9/09 Hofmeister 317-86 Wiese 31786 K-arsel 158-28 X Lake 158-28 Hall 158-126 Bulger 15828 Eaton 317-132 Harris. f

Yates et al.

Nagel' 158-123 X Morrison 158-125 Cobb -2. 263-33 Cobb 158-126 X Proutyf-et al. 158-125 X 'Deziel 158-125 JAMES w. WESTHAVER, Primary Examiner.

, FREDERICKL. MATTESON, JR., PERCY L.

PATRICK, Examiners; y

UNITED STATES PATENT OFFICE CTIICATE @F CQRRECTION Patent No; 3,17%469 March 2, 1965 Harry A0 Mudd It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 10, line 51, for "head" read heat Signed and sealed this 21st day of December 1965c Commissioner of Patents ERNEST W. SWIDER Attesting Officer 

1. AN ELECTRICALLY ENERGIZED DIRECT IGNITION SYSTEM FOR A FUEL BURNER HAVING A SOURCE OF FUEL CONTROLLED BY AN ELECTRICALLY OPERATED VALVE COMPRISING A BURNER CIRCUIT CONNECTED TO SAID ELECTRICALLY OPERATED VALVE AND THROUGH SWITCH MEANS TO A SOURCE OF ELECTRIC POWER, A TIMER SWITCH CONNECTED IN SAID BURNER CIRCUIT WITH SAID SOURCE OF ELECTRIC POWER FOR ENERGIZING SAID ELECTRICALLY OPERATED VALVE TO OPEN AND FOR DE-ENERGIZING SAID ELECTRICALLY OPERATED VALVE TO CLOSE, A TIMER ELEMENT IN SAID TIMER SWITCH, A STARTING CIRCUIT CONNECTED WITH SAID SOURCE OF ELECTRIC POWER AND WITH SAID BURNER CIRCUIT FOR INITIALLY ENERGIZING SAID BURNER CIRCUIT TO OPEN SAID ELECTRICALLY OPERATED VALVE WHEN SAID SWITCH MEANS ARE CLOSED, AN IGNITOR CIRCUIT CONNECTED WITH SAID SOURCE OF ELECTRIC POWER BY SAID TIMER SWITCH TO BE ENERGIZED AND DE-ENERGIZED BY CLOSING AND OPENING OF SAID TIMER SWITCH WHEN SAID SWITCH MEANS ARE CLOSED, A PAIR OF MAKE AND BREAK IGNITION POINTS IN SAID IGNITOR CIRCUIT CONNECTED IN SERIES WITH SAID TIMER SWITCH, A FLAME SWITCH RESPONSIVE TO EHAT FROM SAID FUEL BURNER FOR CONNECTING AND DISCONNECTING SAID SOURCE OF ELECTRIC POWER AND SAID STARTING CIRCUIT, MEANS IN SID STARTING CIRCUIT CONTROLLED BY SAID FLAME SWITCH WHEN CLOSED TO INITIATE THE TIME ELEMENT IN SAID TIMER SWITCH AND TO DE-ENERGIZE THE TIMER ELEMENT WHEN SAID FLAME SWITCH OPENS AT HIGH TEMPERATURES, AND MEANS TO MOVE SAID MAKE AND BREAK IGNITION POINTS INTO AND OUT OF CONTACT IN RESPONSE TO OPENING OF SAID ELECTRICALLY OPERATED VALVE AS LONG AS SAID FLAME SWITCH REMAINS CLOSED AND SAID BURNER CIRCUIT IS ENERGIZED. 